PURPOSE: Case-based simulations are powerful training tools that can enhance learning and drive behavior change. This is an overview of the design/development of Dental Decision Simulation (DDSim), a web-based simulation of an electronic dental record (EDR). The purpose was to use DDSim to train dentists to make evidence-based treatment planning decisions consistent with current evidence. This simulated EDR provides case-based information in support of a set of defined evidence-based learning objectives. METHODS: The development of this complex simulation model required coordinated efforts to create several components: identify behavior changes, case authoring mechanism, create virtual patient visits, require users to make treatment plan decisions related to learning objectives, and a feedback mechanism to help users recognize departures from those learning objectives. This simulation was evaluated in a 2-arm, clinic-randomized, controlled pilot study examining the extent to which DDSim changed dentists' planned treatment to conform to evidence-based treatment guidelines relative to change in dentists not exposed to DDSim. Outcomes were measured by comparing preintervention and postintervention patient EDR treatment data. RESULTS: Changes in behavior over time did not favor intervention or control clinics. CONCLUSION: DDSim provides a standardized learning platform that cannot be achieved through the use of live patients. Both live patients and case-based simulations can be used to transfer knowledge and skill development. DDSim offers the advantage of providing a platform for developing treatment planning skills in a low-risk environment. However, further research examining behavior change is needed.